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How do we know that this is related to his ATI card?
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John S GruberOct 7 '12 at 17:33

Because thats the only "odd" thing about it. I run Unity just fine on machines with slower CPUs and less RAM. Now, I don't go off running a private cloud, but I can use it for basic web browsing and stuff.
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jrg♦Oct 8 '12 at 16:40

3 Answers
3

Ubuntu 11.10 and beyond play well with at least a Dual-Core processor. I recommend you trying some lighter editions, such as Xubuntu, or Lubuntu. Other derivatives from Ubuntu might be elementary OS, (beware as stable release Jupiter 0.1 is outdated, but I still use it on netbooks), or Linux Mint, which you may try the new LXDE version (faster but less eye candy). Good luck! ;)

Also, by hardware I may suppose you are talking of Windows XP, which in that case, minimum requirements are similar to the ones on Lubuntu. Ubuntu 11.10 is slightly heavier for your graphics in comparison to Windows 7 Home Premium.

The problem is Compiz - it's a resource hog. Recent versions of Ubuntu [Desktop] use Compiz which requires a fairly recent CPU & GPU (within the last 3 years) to behave well, otherwise you'll notice severe choppiness and general "slowness." This was my experience with a Pentium 4 and an AGP Radeon. With Ubuntu versions prior to 11.04 I had no problem with that older hardware, but as soon as I upgraded to a version using Compiz that older hardware just became unbearable. I built a new computer with a core i7 and Radeon 7870 and now Ubuntu 12.04 is responsive and snappy. Your Celeron and Radeon 9250 are probably not powerful enough to run all the Compiz eye-candy so you may want to try using a version/distro of Linux that doesn't depend on Compiz, otherwise consider upgrading your hardware.